The Chlamydomonas test: A new phytotoxicity test based on the inhibition of algal photosynthesis enables the assessment of hazardous leachates from waste disposals in salt mines

Based on the inhibition of photosynthesis of the green-alga Chlamydomonas a new phytotoxicity test was elaborated. Feasibility was verified by comparative studies with standard phytotoxicity tests with Lemna (growth) and Lepidium (root elongation), using both solutions with distinct heavy metals and complex mixtures of heavy metals. A major advantage of the Chlamydomonas test is its salt tolerance. When toxic brines, e.g. leachates from heavy metal wastes deposited in salt mines, shall be analyzed the standard tests failed because of the salt sensitivity of Lemna and Lepidium. In contrast, the Chlamydomonas test revealed valid information on the phytotoxicity of such leachates.